Render out so darker than preview (auto exposure closed) (SOLVED)

last question sir ,after those setting i am able to take render without any problem in 1920x1080 but geting crash with 4k render .Its like , i can take 4k render for shot 1 but cant for shot 2 and shot 3 and again can take 4k render for shot 4 and etc… before those setting i was able to take 4k render for my all shots (with that dark problem ofcourse )
which settings could be reason of crash ,do you have any idea ?

crash error ;
Assertion failed: [File D:/Build/++UE4/Sync/Engine/Source/Runtime/Windows/D3D11RHI/Private/D3D11Util.cpp] [Line: 249] Direct3DDevice->CreateComputeShader( (void*)CodePtr, CodeSize, NULL, Shader->Resource.GetInitReference() ) failed at D:/Build/++UE4/Sync/Engine/Source/Runtime/Windows/D3D11RHI/Private/D3D11Shaders.cpp:243 with error E_INVALIDARG

UE4Editor_Core
UE4Editor_Core
UE4Editor_Core
UE4Editor_Core
UE4Editor_D3D11RHI
UE4Editor_D3D11RHI
UE4Editor_D3D11RHI
UE4Editor_D3D11RHI
UE4Editor_RenderCore
UE4Editor_RenderCore
UE4Editor_RenderCore
UE4Editor_RenderCore
UE4Editor_RenderCore
UE4Editor_Renderer
UE4Editor_RenderCore
UE4Editor_RenderCore
UE4Editor_Renderer
UE4Editor_Renderer
UE4Editor_Renderer
UE4Editor_Renderer
UE4Editor_Renderer
UE4Editor_Renderer
UE4Editor_Renderer
UE4Editor_Renderer
UE4Editor_Core
UE4Editor_Core
UE4Editor_RenderCore
UE4Editor_RenderCore
UE4Editor_Core
UE4Editor_Core
kernel32
ntdll

Edit: Enable alpha channel support in post processing (experimental one ) was the reason to get crash with 4k